Forgot passcode need to factory reset
How do I do a factory reset without my passcode or a computer with iTunes?
iPhone 8 Plus
Question marked as
There is an Apple article that explains what to do if you have forgotten an iPhone or iPad passcode. Click on the following link: If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support
If that option is not available, you will need to use a computer. See: If you forgot your iPhone passcode - Apple Support